You've introduced a new assumption though: that a unvaccinated person has and transmits covid. You must apply the probabilities to that initial assumption as well. Probability of having covid * probability of transmitting covid * probability that the person you transmit to has series harm done.

>Also vaccine requirements aren’t anything new

This is an argument that I've also seen but think appeals to "well we've been doing something similar already." I don't think that justification holds much water, especially in this time period where we are questioning a lot of foundational social assumptions.

To your direct question about bar for acceptance, I think people can generally establish a good bar, but they have to be given accurate probabilities, and those have been hidden from us in favor of vague fear mongering.